Allow settings.py postprocessor to be None (#182)

Author: Archmonger

CHANGELOG.md

@@ -38,6 +38,10 @@ Using the following categories, list your changes in this order:
 
 -   Warning W018 (`Suspicious position of 'reactpy_django' in INSTALLED_APPS`) has been added.
 
+### Changed
+
+-   The default postprocessor can now disabled by setting `REACTPY_DEFAULT_QUERY_POSTPROCESSOR` to `None`.
+
 ## [3.5.0] - 2023-08-26
 
 ### Added

docs/src/features/settings.md

@@ -26,7 +26,7 @@ These are ReactPy-Django's default settings values. You can modify these values
 | `REACTPY_DATABASE` | `#!python "default"` | `#!python "my-reactpy-database"` | Database used to store ReactPy session data. ReactPy requires a multiprocessing-safe and thread-safe database.<br/>If configuring `REACTPY_DATABASE`, it is mandatory to use our database router like such:<br/>`#!python DATABASE_ROUTERS = ["reactpy_django.database.Router", ...]` |
 | `REACTPY_SESSION_MAX_AGE` | `#!python 259200` | `#!python 0`, `#!python 60`, `#!python 96000` | Maximum seconds to store ReactPy session data, such as `args` and `kwargs` passed into your component template tag.<br/>Use `#!python 0` to not store any session data. |
 | `REACTPY_URL_PREFIX` | `#!python "reactpy/"` | `#!python "rp/"`, `#!python "render/reactpy/"` | The prefix to be used for all ReactPy websocket and HTTP URLs. |
-| `REACTPY_DEFAULT_QUERY_POSTPROCESSOR` | `#!python "reactpy_django.utils.django_query_postprocessor"` | `#!python "example_project.my_query_postprocessor"` | Dotted path to the default `reactpy_django.hooks.use_query` postprocessor function. |
+| `REACTPY_DEFAULT_QUERY_POSTPROCESSOR` | `#!python "reactpy_django.utils.django_query_postprocessor"` | `#!python None`, `#!python "example_project.my_query_postprocessor"` | Dotted path to the default `reactpy_django.hooks.use_query` postprocessor function. Postprocessor functions can be async or sync, and the parameters must contain the arg `#!python data`. Set `REACTPY_DEFAULT_QUERY_POSTPROCESSOR` to `#!python None` to globally disable the default postprocessor. |
 | `REACTPY_AUTH_BACKEND` | `#!python "django.contrib.auth.backends.ModelBackend"` | `#!python "example_project.auth.MyModelBackend"` | Dotted path to the Django authentication backend to use for ReactPy components. This is only needed if:<br/> 1. You are using `AuthMiddlewareStack` and...<br/> 2. You are using Django's `AUTHENTICATION_BACKENDS` setting and...<br/> 3. Your Django user model does not define a `backend` attribute. |
 | `REACTPY_BACKHAUL_THREAD` | `#!python False` | `#!python True` | Whether to render ReactPy components in a dedicated thread. This allows the webserver to process web traffic while during ReactPy rendering.<br/>Vastly improves throughput with web servers such as `hypercorn` and `uvicorn`. |
 | `REACTPY_DEFAULT_HOSTS` | `#!python None` | `#!python ["localhost:8000", "localhost:8001", "localhost:8002/subdir" ]` | The default host(s) that can render your ReactPy components. ReactPy will use these hosts in a round-robin fashion, allowing for easy distributed computing.<br/>You can use the `host` argument in your [template tag](../features/template-tag.md#component) as a manual override. |

src/reactpy_django/checks.py

@@ -330,12 +330,12 @@ def reactpy_errors(app_configs, **kwargs):
             )
         )
     if not isinstance(
-        getattr(settings, "REACTPY_DEFAULT_QUERY_POSTPROCESSOR", ""), str
+        getattr(settings, "REACTPY_DEFAULT_QUERY_POSTPROCESSOR", ""), (str, type(None))
     ):
         errors.append(
             Error(
                 "Invalid type for REACTPY_DEFAULT_QUERY_POSTPROCESSOR.",
-                hint="REACTPY_DEFAULT_QUERY_POSTPROCESSOR should be a string.",
+                hint="REACTPY_DEFAULT_QUERY_POSTPROCESSOR should be a string or None.",
                 obj=settings.REACTPY_DEFAULT_QUERY_POSTPROCESSOR,
                 id="reactpy_django.E007",
             )

src/reactpy_django/config.py

@@ -53,15 +53,20 @@
 _default_query_postprocessor = getattr(
     settings,
     "REACTPY_DEFAULT_QUERY_POSTPROCESSOR",
-    None,
+    "UNSET",
 )
-REACTPY_DEFAULT_QUERY_POSTPROCESSOR: AsyncPostprocessor | SyncPostprocessor | None = (
-    import_dotted_path(
-        _default_query_postprocessor
-        if isinstance(_default_query_postprocessor, str)
-        else "reactpy_django.utils.django_query_postprocessor",
+REACTPY_DEFAULT_QUERY_POSTPROCESSOR: AsyncPostprocessor | SyncPostprocessor | None
+if _default_query_postprocessor is None:
+    REACTPY_DEFAULT_QUERY_POSTPROCESSOR = None
+else:
+    REACTPY_DEFAULT_QUERY_POSTPROCESSOR = import_dotted_path(
+        "reactpy_django.utils.django_query_postprocessor"
+        if (
+            _default_query_postprocessor == "UNSET"
+            or not isinstance(_default_query_postprocessor, str)
+        )
+        else _default_query_postprocessor
     )
-)
 REACTPY_AUTH_BACKEND: str | None = getattr(
     settings,
     "REACTPY_AUTH_BACKEND",

src/reactpy_django/types.py

@@ -105,9 +105,9 @@ class QueryOptions:
     are optional `postprocessor_kwargs` (see below). This postprocessor function must return
     the modified `data`.
 
-    If `None`, the default postprocessor is used.
+    If unset, REACTPY_DEFAULT_QUERY_POSTPROCESSOR is used.
 
-    This default Django query postprocessor prevents Django's lazy query execution, and
+    ReactPy's default django_query_postprocessor prevents Django's lazy query execution, and
     additionally can be configured via `postprocessor_kwargs` to recursively fetch
     `many_to_many` and `many_to_one` fields."""
 

tests/test_app/components.py

@@ -8,6 +8,7 @@
 from django.shortcuts import render
 from reactpy import component, hooks, html, web
 from reactpy_django.components import view_to_component
+from reactpy_django.types import QueryOptions
 
 from test_app.models import (
     AsyncForiegnChild,
@@ -602,3 +603,17 @@ def custom_host(number=0):
         },
         f"Server Port: {port}",
     )
+
+
+@component
+def broken_postprocessor_query():
+    relational_parent = reactpy_django.hooks.use_query(
+        QueryOptions(postprocessor=None), get_relational_parent_query
+    )
+
+    if not relational_parent.data:
+        return
+
+    mtm = relational_parent.data.many_to_many.all()
+
+    return html.div(f"This should have failed! Something went wrong: {mtm}")

tests/test_app/templates/base.html

@@ -91,6 +91,9 @@ <h1>ReactPy Test Page</h1>
   <hr>
   <div id="invalid_host_error">{% component "test_app.components.hello_world" host="https://example.com/" %}</div>
   <hr>
+  <div id="broken_postprocessor_query">
+    {% component "test_app.components.broken_postprocessor_query" %}</div>
+  <hr>
 </body>
 
 </html>

tests/test_app/tests/test_components.py

@@ -370,3 +370,8 @@ def test_invalid_host_error(self):
         broken_component = self.page.locator("#invalid_host_error")
         broken_component.wait_for()
         self.assertIn("InvalidHostError:", broken_component.text_content())
+
+    def test_broken_postprocessor_query(self):
+        broken_component = self.page.locator("#broken_postprocessor_query pre")
+        broken_component.wait_for()
+        self.assertIn("SynchronousOnlyOperation:", broken_component.text_content())